By Alex Frew McMillan and Eveline Danubrata HONG KONG/SINGAPORE | Sun Sep 30, 2012 5:17pm EDT HONG KONG/SINGAPORE (Reuters) - At the Happy Community housing development in Beijing, China's largest property developer is setting aside 24,000 square meters (258,000 sq ft) for active seniors to test whether this rapidly ageing nation will pay for Western-style retirement living. China Vanke Co Ltd 000002.SZ thinks there is "ample room for development" in the senior care sector, a spokesman said, and is testing a second pilot project for seniors in the coastal city of Qingdao. The company plans to open a showroom in the Chinese capital over the Lunar New Year in February. Overseas players including New York-based hedge fund Fortress Investment Group LLC (FIG.N ) and China Senior Care, backed by one of the principals of U.S. private developer Lerner Enterprises, are also investi...